The invention relates to a metallurgic vessel, in particular a ladle for the transport of molten metals.
A metallurgic vessel is known from DE 195 38 530 C1. It consists of a metal casing which receives the refractory lining and is composed of individual tubular sections and which has two reinforcing rings running in the circumferential direction. The vessel further has two vessel carrying lugs which, located opposite one another on the outside of the metal casing, are supported in each case by a plate connected to the reinforcing rings. In this known design, the reinforcing rings are an integral part of the metal casing. It is also known to weld the reinforcing rings to the metal casing (DE-AS 29 01 011). The disadvantage of all the known designs is that they can be produced only at a high outlay in forming and welding terms and the differing rate of wear of the main components is not taken into account.
A somewhat differently designed metallurgic vessel is known from DE 29 05 283 B2. This is a tiltable and/or rotating steel mill converter. The converter is held by means of individual or interconnected carrying claws fastened to the vessel wall and prestressing units which are arranged parallel to and/or perpendicularly to the vessel longitudinal axis and make the connection between the carrying claws. A peripheral carrying ring is provided with a plate and vessel carrying lugs. The disadvantage of this design is the need to produce and arrange a plurality of prestressing units which considerably increase the construction costs.
Another converter design is disclosed in U.S. Pat. No. 3,503,559. In this design, two carrying rings are firmly connected to the metal casing at a parallel distance from one another. So that the converter can be exchanged in a simple way, the plates connected to the vessel carrying lugs are designed as individual elements which are connected releasably to one another by means of bolts with the aid of altogether four holding arms surrounding the metal casing. In order to guide the vessel under radial and axial expansion, the carrying rings have axially extending webs which engage into correspondingly designed recesses of the plates. The vessel is prevented from being displaced on one side by an axially extending web of the carrying ring, said web engaging into a corresponding recess in the holding arms.
The object of the invention is to provide a metallurgic vessel, in particular a ladle for the transport of molten metals, which can be produced more simply and the design of which takes into account the differing rates of wear.
According to the invention, the carrying framework has two carrying rings which are located at a parallel distance from one another and, together with the plate and the vessel carrying lugs, form an independent unit which is at a distance from the outside of the metal casing and is arranged with axial play between the carrying claws. This design is based on the idea that, particularly in the case of the ladle, the carrying framework has the function of transferring the most diverse transport situations into the ladle container without any reaction. The proposed arrangement has the advantage that the carrying framework and the container can be separated from one another at any time and the carrying framework can be used more frequently. It is known that the container has only a limited operating time of X melts, and must then be readjusted and, if necessary, repaired. In the designs known hitherto, the carrying framework cannot be used during readjustment and repair, since it is an integral part of the container. In the inventive design, then, it is advantageous that, at the end of a container trip, that is to say after the filling and emptying of, for example, 100 melts, the securing ring can be removed and the container can be pushed out of the carrying framework forming an independent unit. Subsequently, for example, it can be overturned, the refractory lining broken out and, if necessary, the metal casing and/or the bottom repaired. Readjustment is thereafter carried out again. During this entire time, the carrying framework used hitherto can be employed again for an already adjusted container. Another advantage of the invention is that the container can expand, unimpeded, in relation to the carrying framework both in the circumferential direction and in the axial direction. This leads to stress reductions, so that the design can be slimmer, that is to say with a smaller wall thickness. In other words, the proposed design makes it possible to produce a thin-walled, lightweight and nevertheless low-deformation container which, moreover, can be manufactured extremely cost-effectively and has considerable advantages in a repair situation.
For smaller vessels with an insignificant melt content and low requirements, it may even be cost-effective to design the container as a disposable article and continue to use the carrying framework as an independent unit. This concept would seem to be expedient for small electric steel mills. Such a simple container would be manufactured from a pipe section, a loose bottom would be inserted and the entire inner surface would be lined monolithically with a refractory compound.
Larger containers with melt contents of, for example, 250 t and above would be produced at a somewhat higher outlay and, if necessary, a frustoconical mount would be attached to the upper edge, so that the container, having a high free rim, is suitable for vacuum treatment and can easily be given a lid.
By an insulating layer being arranged in the contact region between the carrying framework and the claws or the securing ring, the heat flow between the hot container and the colder carrying framework can be reduced. Since there is no solid-state contact between the carrying framework and the container, apart from these contact bridges, the carrying framework can be designed more cost-effectively with regard to thermal stability.
For receiving the container in the carrying framework, it is necessary to have at least two claws located opposite one another and firmly attached to the metal casing. So that no tilting of the container can occur, preferably three or four claws will be provided. Alternatively, the claws may also be designed as a ring surrounding the metal casing. This ring may be welded onto the metal casing or be an integral part of the metal casing. In the latter case, this would lead to a desired reinforcement of the upper container edge.